Flip of a figure about an axis d that is perpendicular to a given direction.
The axis d is called the line of reflection.
The axis d is called the line of reflection.
Symmetry about an axis d perpendicular to a given direction.
The axis d is called the line of reflection.
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- The term “reflection” is a synonym for orthogonal symmetry.
- Frieze patterns and tessellations can be created by applying reflections.
Notation
A reflection is often denoted by the letter “r”. A subscript may also be added to represent its axis. For example : rd refers to a reflection r across an axis d.
Properties
The invariants under a reflection in a plane are as follows:
A reflection also preserves:
- the perimeter and area of plane figures;
- the measures of angles.
The orientation of a plane is not preserved under a reflection, since a reflection is a flip that reverses the orientation of the plane.